eqnalign – Make eqnarray behave like align

The pack­age makes eq­nar­ray en­vi­ron­ment be­have
like align from ams­math'. It is in­tended for
quick-fix­ing doc­u­ments that use eq­nar­ray.
In cases where it fails, man­ual con­ver­sion to align
is re­quired, but these cases should be sel­dom.